Time for children: A study of parent's time allocation

The trade-off between parents' time with their own kids and market work, and its dependence on out-of-home day care is analyzed in a simultaneous equation framework. Economic incentives primarily work through decisions about market work, while the direct effects on time with children are weak. The results suggest that a change in the mother's working hours has less influence on the parents' time with their children than a change in the father's working hours. This would imply that a policy working to increase the time with people's own children should primarily influence the father's work hours. We also find that parents prefer joint activities with their children, and that out-of-home child care is not chosen as a substitute for own time with children. Received: 1 February 2000/Accepted: 22 May 2002 All correspondence to Daniel Hallberg. Helpful comments and suggestions from Henry Ohlsson and anonymous referees are gratefully acknowledged. We also appreciate comments from Martin Browning and seminar participants at Uppsala and Ume? universities. Financial support from the Swedish Council for Social Research (SFR) is gratefully acknowledged. Responsible editor: John F. Ermisch.     

Combinatorics of TCP reordering

We study a combinatorial problem motivated by a receiver-oriented model of TCP traffic from Istrate et al. (2006), that incorporates information on both arrival times, and the dynamics of packet IDs. An important component of this model is a many-to-one mapping FB from sequences of IDs into a sequence of buffer sizes. We show that: i) Given a buffer sequence B, constructing a sequence A of IDs that belongs to the preimage of B is no harder than finding matchings in bipartite graph. ii) Counting the number of sequences A of packet IDs that belong to the preimage of B can be done in linear time in the special case when there exists a constant upper bound on the maximum entry in B. iii) This problem also has a fully polynomial randomized approximation scheme when we have a constant upper bound on the number of repeats in the packet sequences in the preimage. We also provide experimental evidence that the two previous results suffice to efficiently count the number of preimages for buffer sequences observed in real TCP data.     

Back for business: The link between foreign experience and entrepreneurship in Latvia

Research shows that return migrants have a higher propensity to set up an entrepreneurial activity or be self-employed compared to non-migrants. We take a multidisciplinary approach and empirically study the case of Latvia as a migration donor country to learn how re-migrants participate in entrepreneurship back at home. We are interested if return migrants can be seen as a vehicle for entrepreneurship development and if it is worth looking at them as agents of business growth and innovation. Not only we measure the fact of being entrepreneurial but also explore sources that contribute to the higher propensity, attitudes to creating own business venture, level of ambitions and population sentiment towards entrepreneurs. Based on a nationally representative adult population survey of 8000 observations, we find that early-stage entrepreneurial activity, established business ownership as well as intrapreneurship for return migrants exceed that of the non-migrant population. The self-perceived capabilities to start business is higher for those who have lived abroad, and fear of failure is lower. Return migrants also have better business networks and higher growth and export ambitions. Latvian return migrant entrepreneurship is not necessity driven but rather motivated by opportunities. Migration experience, length of stay aboard and capital accumulated abroad are found to be significant predictors of probability to become entrepreneur when controlled for socioeconomic and personal factors.     

Wage Setting in Sweden: An Empirical Test of a Barebones Union Model

ABSTRACT In this paper a simple monopoly union model for the Swedish economy is presented and estimated. Interest is focused on the union's objectives. The results indicate that two popular representations of union objectives — wage bill and rent maximisation — are rejected by the data. Instead, preferences are highly concave in the wage rate, with an estimated degree of relative risk aversion well above unity evaluated at sample means.     

Targeted estimation of state occupation probabilities for the non-Markov illness-death model

We use semi-parametric efficiency theory to derive a class of estimators for the state occupation probabilities of the continuous-time irreversible illness-death model. We consider both the setting with and without additional baseline information available, where we impose no specific functional form on the intensity functions of the model. We show that any estimator in the class is asymptotically linear under suitable assumptions about the estimators of the intensity functions. In particular, the assumptions are weak enough to allow the use of data-adaptive methods, which is important for making the identifying assumption of coarsening at random plausible in realistic settings. We suggest a flexible method for estimating the transition intensity functions of the illness-death model based on penalized Poisson regression. We apply this method to estimate the nuisance parameters of an illness-death model in a simulation study and a real-world application.     

The will to sanction: How sensitive are caseworkers to recipients’ responsibility when imposing sanctions on non-compliance in a welfare-to-work programme?

The activation trend in social policy entails that caseworkers on the frontlines of the welfare state are expected to decide ‘reasonable’ activation requirements for clients and when and how non-compliance should be sanctioned. This study investigates how caseworkers form judgements about their clients’ personal responsibility when activation requirements are violated and how their judgements about responsibility matter for the sanctions they impose. We find that caseworkers are sensitive to personal responsibility, varying the motivation for not fulfilling the activation requirement from a case where the client has less control (circumstances) to one with more control (choice) more than doubles sanctions.